This is a classic example of why a blind spot mirror is so effective
This is the view from the drivers side of the vehicle
In the normal mirror There appears to be NOTHING at the side of our vehicle
HOWEVER in the blind spot mirror we can clearly see that we are still alongside a car
So to try and move back to the left at this point would be a catastrophic mistake
WITHOUT THE BLIND SPOT MIRROR - YOU WOULDN'T KNOW THAT CAR WAS THERE!!